Parasite protein spurs child malaria vaccine efforts

The findings concern one of a number of proteins that are found on the surface of human red blood cells infected by the parasites. These proteins help the malaria parasite survive in the human body by stopping the removal of blood cells in the spleen, therefore allowing the parasite to reproduce.

Malaria parasites produce different proteins depending on whether the person infected is a young child or an older person with a well-developed immune response. As the human body fights the disease, it develops an immune response to it by producing antibodies against the malaria proteins. This reduces the range of proteins the parasite can produce and still survive, and causes it to produce less harmful proteins.

Scientists hope that a vaccine based on such proteins found only in childhood malaria could accelerate this process and, with it, the development of immunity. But until now, they haven't been able to identify the proteins involved.

This week, researchers from Denmark, the Netherlands, the United Kingdom and Tanzania report in The Journal of Experimental Medicine that they have identified one of these, a protein produced specifically during severe childhood malaria as PfEMP1. They have been able to show that this protein causes infected cells to become stuck in blood vessels instead of being removed in the spleen. Infected blood cells eventually burst leading to life-threatening fever.

"Our data suggest that it is possible to develop a disease-ameliorating vaccine against severe malaria that is based on [these childhood malaria] proteins," they write. Furthermore, unlike other malaria proteins, PfEMP1 is structurally similar between parasites in West and East Africa, increasing the potential for a universal immunity-boosting vaccine.